A cost database is a computerized database of cost estimating information, which is normally used with

construction estimating software Construction cost estimating software is computer software designed for contractors to estimate construction costs for a specific project. A cost estimator will typically use estimating software to estimate their bid price for a project, which wil ...

to support the formation of cost estimates. A cost database may also simply be an electronic reference of cost data.

Overview

A cost

database In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases sp ...

includes the electronic equivalent of a cost book, or cost reference book, a tool used by estimators for many years. Cost books may be internal records at a particular company or agency, or they may be commercially published books on the open market. AEC teams and federal agencies can and often do collect internally sourced data from their own specialists, vendors, and partners. This is valuable personalized cost data that is captured but often doesn't cover the same range that commercial cost book data can. Internally sourced data is difficult to maintain and do not have the same level of developed user interface or functionalities as a commercial product. The cost database may be stored in

relational database management system A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A system used to maintain relational databases is a relational database management system (RDBMS). Many relatio ...

, which may be in either an open or

proprietary format A proprietary file format is a file format of a company, organization, or individual that contains data that is ordered and stored according to a particular encoding-scheme, designed by the company or organization to be secret, such that the decodi ...

, serving the data to the cost estimating software. The cost database may be hosted in the

cloud In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, frozen crystals, or other particles suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may co ...

. Estimators use a cost database to store data in structured way which is easy to manage and retrieve.

Details

Costing data

The most basic element of a cost estimate and therefore the cost database is the estimate line item or work item. An example is "Concrete, 4000 psi (30 MPa)," which is the description of the item. In the cost database, an item is a

row Row or ROW may refer to: Exercise *Rowing, or a form of aquatic movement using oars *Row (weight-lifting), a form of weight-lifting exercise Math *Row vector, a 1 × ''n'' matrix in linear algebra. *Row (database), a single, implicitly structured ...

or record in a

table Table may refer to: * Table (furniture), a piece of furniture with a flat surface and one or more legs * Table (landform), a flat area of land * Table (information), a data arrangement with rows and columns * Table (database), how the table data ...

(of items) and the description is a

column A column or pillar in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below. In other words, a column is a compression member. ...

or field for that record. Concrete may also be considered to be a material

resource Resource refers to all the materials available in our environment which are technologically accessible, economically feasible and culturally sustainable and help us to satisfy our needs and wants. Resources can broadly be classified upon their ...

. In some systems, estimate line items and resources are the same, in other systems, various resources may be included with a line item. Other examples of resources are

labor Labour or labor may refer to: * Childbirth, the delivery of a baby * Labour (human activity), or work ** Manual labour, physical work ** Wage labour, a socioeconomic relationship between a worker and an employer ** Organized labour and the labour ...

resources, such as carpenters, and

equipment Equipment most commonly refers to a set of tools or other objects commonly used to achieve a particular objective. Different job Work or labor (or labour in British English) is intentional activity people perform to support the needs and ...

resources, such as cranes. Labor and equipment resources can be combined into a crew, which is then the assumed crew which will install the item or perform the work. Resources and crews can be stored as data in the cost database and can also be related to work items. Examples of cost database line items: Examples of cost database labor resources: Examples of cost database equipment resources: Examples of cost database crews: {, class="wikitable" , - !Identifier !Description !Unit of Measure !Resource 1 !Quantity 1 !Resource 2 !Quantity 2 !Resource 3 !Quantity 3 , - , CP-01 , Concrete placement , hour , CA , 1 , LA , 3 , cv1 , 1 , - , EX-01 , General excavation , hour , OP , 1 , LA , 2 , ex2 , 1

Factor and adjustment data

Various factors and adjustments may be useful in the estimating process. Some examples include: * Factors to adjust costs from one location to another * Factors to adjust costs from one time to another * Currency conversion factors * Sales and use tax rates * Other tax, insurance, and bond rates * Overhead factors

Organizational data

Data which may be used to organize a cost estimate into groups and levels, and to summarize the cost details can also be part of a cost database. A popular coding system which can be applied to construction cost estimates is

MasterFormat MasterFormat is a standard for organizing specifications and other written information for commercial and institutional building projects in the U.S. and Canada. Sometimes referred to as the "Dewey Decimal System" of building construction, MasterFor ...

. Another coding method is Uniformat."Uniformat," Construction Specifications Institute, http://www.csinet.org/uniformat Also, various types of

work breakdown structure A work-breakdown structure (WBS) in project management and systems engineering is a deliverable-oriented breakdown of a project into smaller components. A work breakdown structure is a key project deliverable that organizes the team's work into ...

s or WBS may be used. It may also be useful to assign the costs to a

chart of accounts A chart of accounts (COA) is a list of financial accounts set up, usually by an accountant, for an organization, and available for use by the bookkeeper for recording transactions in the organization's general ledger. Accounts may be added t ...

or COA (a.k.a. Code of Accounts). Other organizational needs include: *Grouping by job cost account *Grouping by subcontractor or vendor *Grouping by material class or type *Grouping by facility, floor, level, location, area, etc. *Grouping by system *Grouping by project phase or stage *Grouping by inside or outside battery limits All of these represent organizational data which can be stored in the cost database and used to support the cost estimate.

Calculational data

Data which can be used to calculate quantities and costs can also be part of a cost database. For example, there are various formulas for calculating the

area Area is the quantity that expresses the extent of a region on the plane or on a curved surface. The area of a plane region or ''plane area'' refers to the area of a shape A shape or figure is a graphics, graphical representation of an obje ...

of shapes, the

volume Volume is a measure of occupied three-dimensional space. It is often quantified numerically using SI derived units (such as the cubic metre and litre) or by various imperial or US customary units (such as the gallon, quart, cubic inch). The de ...

of solids or spaces, and the

weight In science and engineering, the weight of an object is the force acting on the object due to gravity. Some standard textbooks define weight as a Euclidean vector, vector quantity, the gravitational force acting on the object. Others define weigh ...

of materials. There are defined unit properties of materials also. Materials each have certain

densities Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek language, Greek letter Rho (letter), rho), although the Latin letter ''D'' ca ...

or unit weights. Reinforcing bars are produced in certain sizes, with certain unit weights. Additionally, data which helps calculate the selection or specification of estimate contents can be included.

References

External links

A Visual Approach to Construction Cost Estimating
Phuwadol Samphaongoen, Marquette University, e-Publications@Marquette Cost engineering Construction